JPH0239992A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To enable clear printing with high density, favorable transfer properties and favorable sharpness of edges of images to the achieved on rough papers as well as on smooth papers by incorporating a modified resin composition comprising a resin and an inorganic material bonded to each other by a coupling agent, into a least one thermally transferable ink layer. CONSTITUTION:A thermal recording medium comprises an intermediate layer and or more thermally transferable ink layers sequentially provided on a base, and at least one of the ink layers comprises a modified resin composition comprising a resin and an organic material bonded to each other by a coupling agent. At the time of application of heat, thermoplastic resin particulates are hardly fused to each other, so that the ink layers can be controlled in elongation properties without losing adhesive forces thereof, and printing with extremely favorable sharpness of discontinuity of ink at edges of printed images can be achieved. Particles of the inorganic material are concentrated on the periphery of the resin composition, and the region in which the density of the inorganic material is low is greater as compared with the case of not using the modified resin. Thus, the possibility of the inorganic material being exposed to the surface of the ink layer is reduced, and the film properties of the ink layer and the easiness of rupture of the ink layer at the edges of the printed images, are controlled without considerable lowering in the adhesive force at the surface of the ink layer.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a thermal transfer recording medium used for thermal transfer recording. [Prior Art] Thermal transfer recording has the general characteristics of thermal recording such that the equipment used is lightweight, compact, noiseless, and has excellent operability and maintainability. It is also characterized by excellent durability of recorded images.
Widely used recently. This heat-sensitive transfer recording generally uses a heat-sensitive transfer material in which a heat-transferable ink layer formed by dispersing a coloring material in a heat-melting material is coated on a sheet-like support. The ink layer is superimposed on the recording medium such as paper so that it is in contact with the recording medium, and heat is supplied from the support side of the thermal transfer material by a thermal head to transfer the melted ink layer to the recording medium. A transferred recorded image is formed on a recording medium according to the shape of heat supply. By the way, in the case of a wax-based thermal transfer ink layer using a wax-based heat-melting material, the ink layer is completely melted by heat application, so the cohesive force of the thermal transfer ink layer is very small, and characters are easily distorted or In the case of a recording medium with poor print abrasion resistance and low surface smoothness, it is not possible to bring the thermal transfer ink layer into contact with the concave portions of the surface unevenness of the recording medium, and it is only possible to contact the convex portions of the surface. It has the disadvantage that the thermal transferable ink layer is not transferred (so-called transfer defect), and the printing quality is significantly reduced. Therefore, for recording materials with low surface smoothness, a method has been considered in which the ink layer is placed in a state where the convex portions on the surface of the recording material are just bridged, and the ink is transferred so as to cover the concave portions. It will be done. For this purpose, the main component is a resin that exhibits stickiness due to the heat energy applied during printing, but does not melt into a low-viscosity liquid, and has high cohesive strength and appropriate flexibility. It is necessary to provide a resin-based thermal transferable ink layer. In the case of a thermal transfer ink layer using such a resin-based heat-melting material, there are no problems in terms of character distortion and scratch resistance. However, when a resin-based thermal transfer ink layer is used, the cohesive force of the thermal transfer ink layer becomes larger than the adhesive force between the thermal transfer ink layer and the support in the non-heat-applied area, and the heat of the thermal transfer ink layer Printing cannot be cut cleanly at the boundary between the heat-applying section and the non-heat-applying section (causing trailing surface transfer), resulting in poor print quality. Therefore, a proposal has been made to solve the above problems by providing an intermediate layer between the support and the thermal transfer ink layer to control the adhesion between the support and the thermal transfer ink layer. However, since the thermally transferable ink layer of such a recording medium is flexible and easily stretches when heat is applied, it stretches at the print end after printing (so-called printing whiskers), which is not preferable. On the other hand, attempts have been made to suppress the elongation of the ink layer and improve its cutting properties by adding inorganic substances to the thermally transferable ink layer. However, in this method, if an inorganic substance is added to improve the cutting ability, the adhesive force decreases, the transferability decreases extremely, and sufficient print density cannot be obtained on paper with a rough surface, which is not preferable. [Problems to be Solved by the Invention] The present invention solves the conventional problems, and while maintaining various thermal transfer performances, it can be used not only for recording materials with good surface smoothness, but also for recording materials with good surface smoothness. This invention was made in order to provide a thermal transfer material that can provide a thermal transfer image with high density and sharpness even to a low-quality recording medium. [Means for Solving the Problems] The present invention provides a thermal transfer recording medium having an intermediate layer and one or more thermal transferable ink layers on a support in this order, in which at least one of the ink layers is bonded to a resin and an inorganic substance by a coupling agent. A thermal transfer recording medium characterized by containing a bonded modified resin composition. For example, when the modified resin composition disclosed in JP-A-59-71316 is used, since silica is attached to the surface or inside of the thermoplastic resin fine particles, the thermoplastic resin fine particles are separated from each other when heat is applied. 6 As a result, we discovered that it is possible to control the stretchability of the thermal transfer ink layer without damaging its adhesive strength (cohesive force, flexibility), and it is possible to obtain very sharp prints, which is the invention of the present invention. completed. Furthermore, in the present invention, the local concentration of the inorganic substance in the thermal transferable ink layer can be higher than when the inorganic substance is added alone. That is, according to the present invention, inorganic particles are concentrated around the modified resin composition. Therefore, even if the same number of inorganic substances is contained, the density of the inorganic substances is larger than when no modified resin is used, and the probability of inorganic substances being exposed on the surface layer of the thermal transferable ink layer of the thermal transfer material is reduced. (As a result, it has become possible to control the film properties and ease of cutting of the thermal transfer ink layer without significantly reducing surface adhesion. Below, refer to drawings as necessary. The present invention will be explained in more detail.In the following description, "%" representing a quantitative ratio will be used.
"Parts" and "parts" are by weight unless otherwise specified. FIG. 1 is a schematic cross-sectional view in the thickness direction of a thermal transfer material in the most basic embodiment used in the recording method of the present invention. In other words, thermal transfer material! is usually formed by sequentially laminating on a sheet-like support 2 an intermediate layer 3 and a thermally transferable ink layer 4 containing a heat-melting material and a modified resin composition. The intermediate layer in the present invention refers to the layer closest to the support side.The intermediate layer 3 has strong adhesion to the support 2 and the thermal transferable ink layer 4 when no heat is applied, but when heat is applied, the intermediate layer 3 is thermally transferable. This makes it easier for the sexual ink H4 to detach from the support 2. In addition to the heat-melting material and the modified resin composition, the thermal transferable ink layer 4 is composed of a colorant, other dispersants, plasticizers, oils, fillers, and the like as necessary. As the support 2, conventionally known films and papers can be used as they are, such as films of relatively heat-resistant plastics such as polyester, polycarbonate, triacetylcellulose, polyamide, polyimide, cellophane, or parchment paper. , condenser paper, etc. can be suitably used. In addition, when using a thermal head as a means for applying heat to a thermal transfer material, the surface of the support that comes into contact with the thermal bed may be coated with silicone resin, fluororesin, polyimide resin, epoxy resin, phenol resin, melamine resin, nitrocellulose, etc. The heat resistance of the support can be improved by providing a heat-resistant protective layer made of the like, or it is also possible to use a support material that could not be used conventionally. The thickness of the support 2 is preferably about 1 to 15 μm when considering a thermal head as a heat source during thermal transfer, but it is preferable to use a heat source such as a laser beam that can selectively heat the thermal transferable ink layer. There are no particular restrictions in this case. The intermediate layer 3 has a strong adhesion to the support 2 and the thermal transfer ink layer 4 when no heat is applied, but is such that the thermal transfer ink layer 4 easily separates from the support 2 when heat is applied. Good to have. Materials that can be used as the intermediate layer 3 include, for example, a mixture of low molecular weight polyethylene oxide and at least one of polyoxyethylene alkyl allyl ether, fatty acid, resin acid, amine, and sulfuric ester salt, and low molecular weight polyethylene oxide and, for example, acrylic resin. , a polar material such as vinyl acetate resin or a wax emulsion is added to the intermediate layer 3 to 50%
% or less, more preferably 30% or less. As the heat-melting material used for the heat-transferable ink layer 4, 7
By using 0% or more of the resin-based heat-melting material, the transferability is significantly improved, and a transferred recorded image with no misalignment of characters and excellent print abrasion resistance can be obtained. The content of the modified resin composition is preferably 3 to 30%, more preferably 6 to 20%, based on the entire thermal transferable ink layer.
%. If the content is less than 3% (δll), it is not possible to suppress the fusion between fine particles, and if it is more than 30%, the adhesive strength of the thermal transfer ink layer will be reduced, which is not preferable. The melting temperature measured by a calorimeter (DSC) is not particularly limited, but is 50°C or higher and 200°C.
It is desirable that the temperature is below ℃. 20 for melting temperature
If it exceeds 0°C, it is undesirable because the type of support will be severely restricted due to heat resistance problems for the support, and the durability of the thermal head will deteriorate. If it is below 50°C, the thermal melting of the resin Even if a transparent material is used, problems such as staining are likely to occur, so it is not preferable. The heat-melting materials contained in the heat-transferable ink N4 include:
Polyolefin resin, polyamide resin,
Polyester resin, epoxy resin, polyurethane resin, polyacrylic resin, polyvinyl chloride resin, cellulose resin, polyvinyl alcohol resin, petroleum resin, phenolic resin, polystyrene resin, vinyl acetate resin, natural Rubber, elastomers such as styrene-butadiene rubber, isoprene rubber, chloroprene rubber,
Polyisobutylene, bolybdenum, etc. are used. FIG. 3 shows a schematic conceptual diagram of the modified resin composition 10. The modified resin composition 10 consists of a resin 7, a coupling agent 8, and an inorganic substance 9, and the resin 7 and the inorganic substance 9 are bonded together using the coupling agent 8. Examples of the resin 7 that can be used here include polyolefin, polystyrene, polyvinyl chloride, nylon, polyphenylene oxide, polyphenylene sulfide, acrylic resin, alkyd resin, melamine resin, epoxy resin, polyamide resin, phenol resin, polyester resin, urethane resin, BR ( butadiene rubber), IR (isoprene rubber), epichlorohydrin, and other thermoplastic resins and elastomers. Coupling agent 8 is a reagent that chemically connects inorganic materials and organic materials or different types of organic material composite systems, or improves affinity through chemical reactions and enhances the functionality of composite materials. Any agent may be used as long as it binds the resin and the inorganic substance, and for example, a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, etc. are used. Examples of the silane coupling agent include vinyltriethoxysilane, vinyltris(β-methoxy-ethoxy)silane, β-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, N- β (aminoethyl) - γ
-Aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, etc. are used. Titanate coupling agents are classified by the type of hydrophilic group; monoalkoxy coupling agents include isopropyl triisostearoyl titanate and isopropyl tridecylbenzenesulfonyl titanate, and coordinate coupling agents include tetraisopropyl bis(dioctyl phosphite).
Titanate, tetra(2,2-diallyloxymethyl-
1-butyl)bis(di-tridecyl)phosphite titanate, and as chelate types, for example, bis(dioctylpyrophosphate)oxyacetate titanate, bis(dioctylpyrophosphate)ethylene titanate, etc. are used. A representative example of the aluminum coupling agent is acetalkoxyaluminum diisopropylate. Inorganic substances 9 include silica, glass, talc, iron powder, alumina, aluminum hydroxide, calcium carbonate, barium sulfate, titanium oxide, magnesium oxide, calcium oxide, mica, carbon black, iron oxide, asbestos,
Zinc white etc. can be used. The average particle size of the inorganic substance 9 is preferably 10 mμ to 1 μm. If the particle size is reduced to 10 mμ or less, the activation energy on the surface of the inorganic substance increases, making it easier to aggregate and difficult to disperse. Also 1μm
If the above is the case, problems such as surface quality deterioration and smearing may occur when coated as a thermal transfer material, which is undesirable. Modified resin composition IO is obtained by treating and bonding these inorganic substances 9, coupling agent 8, and resin 7 by a dry method, a solvent slurry method, a wet method, or the like. The ratio of the inorganic substance 9 to the resin 7 in the modified resin composition IO is preferably 15 to 500 parts, more preferably 30 to 300 parts, based on 100 parts of the resin. Inorganic matter 9 is 5
If the amount is more than 00 parts, the amount of inorganic substances that cannot be coupled with the resin increases, which deteriorates the stability of the solution over time, and if it is less than 15 parts, the effect of suppressing elongation cannot be obtained sufficiently, which is not preferable. This modified resin composition 1O is added to the entire layer of the thermal transfer ink 14 so that the content of inorganic substances is 1 to 30% to control cohesion, flexibility, and ease of spread, and to achieve sharp printing. You can get it. If the content is too large, the adhesive force to the recording medium will decrease, which is not preferable. The thermal transfer ink layer may contain other substances other than resins such as spermaceti wax, beeswax, lanolin, carnauba wax,
Natural waxes such as candelilla wax, montan wax, and ceresin wax, petroleum waxes such as paraffin wax and microcrystalline wax, synthetic waxes such as oxidized waxes, ester waxes, and Fischer-Tropsch waxes, lauric acid, myristic acid, valmitic acid, and stearic acid. , higher fatty acids such as behenic acid, higher alcohols such as stearyl alcohol and behenyl alcohol, esters such as sucrose fatty acid ester, sorbitan fatty acid ester, amides such as oleylamide, plasticizers, and oils such as mineral oil and vegetable oil as appropriate. It is preferable to mix them and adjust the melting temperature of the thermally transferable ink layer 4 to 50°C or more and less than 200°C. As the coloring agent, various dyes and pigments widely used in the field of printing and recording are used. The content of the colorant is suitably in the range of 3 to 60% based on the total amount of the thermal transferable ink layer 4 and the intermediate layer 3. Further, if necessary, additives such as a dispersant or a filler made of fine metal powder, inorganic fine powder, metal oxide, etc. may be added to the thermal transferable ink layer 4. Further, the layer structure of the thermal transferable ink layer 4 is not particularly limited to a single layer structure containing the above-mentioned modified resin composition, heat-melting material, colorant, dispersant, plasticizer, filler, etc.
It may be functionally separated into two layers: a layer with the function of expressing adhesive force to the recording medium when heated by the thermal head and a layer with the coloring function, or three or more layers if additional functions are added. It may have a layered structure. At this time, the modified resin composition may be placed in any layer as long as it is contained in at least one layer. Specifically, the colorant used in the recording medium of the present invention is as follows:
For example, carbon black, nigrosine dye, lamp black, Sudan Black SM, First Niro G, Benzidine 20-, Pigment Yellow, Indo First Orange, Irgazine Red, Varanitroaniline Red, Toluidine Red, Carmine FB, Permanent Bordeaux FRR, Pigment Orange R1
Lysol Red 2G, Lake Red C10-Damine FB, Rhodamine B Lake, Methyl Violet B
Lake, Phthalocyanine Blue, Pigment Blue, Brilliant Green B, Phthalocyanine Green, Oil Yellow GG, Zapon Fast Yellow CGG,
Kayaset Y963, Kayaset YG, Sumiblast・
Erow GG, Zabon First Orange RR, Oil Scarlet, Sumiblast Orange 05 Orazole Brown G1 Pomelo First Scarlet CG, Eisens Viron Red BE)! , oil pink O
P, Victoria Blue F4R, First Gen Blue 5
One or more of known dyes and pigments such as 007, Sudan Blue, and Oil Peacock Blue can be used. As shown in FIG. 2, when the thermal transferable ink layer 4 has a 2N configuration, the colorant is preferably contained in the first ink layer 5, but it may be contained in the intermediate layer 3 or the second ink N6. . In the case of a two-layer structure, the content of the colorant is preferably in the range of 3 to 60% based on the entire thermal transfer ink layer and the intermediate layer 3. If it is less than 3%, the density will be low, and if it is more than 60%, the transferability will deteriorate. The first ink layer 5 is made of a heat-fusible material and a colorant, and contains a modified resin composition dispersant, a plasticizer, a filler, etc. as necessary, and is made of a single-layer thermal transferable ink layer 4 described above. The materials can be used as is. The second ink layer 6 is made of a material with high adhesive strength to the recording medium.
For example, olefin homopolymers or copolymers such as polyethylene, polypropylene, polyisobutylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, or derivatives thereof, polyamide, polyester , polyurethane or acrylic heat-sensitive adhesives, and styrenic block copolymers such as styrene-isobutylene, styrene-butadiene, and styrene-ethylene-butylene, either alone or in combination as appropriate. Depending on the situation, a modified resin composition may be added, and tackifiers such as alicyclic hydrocarbons, terpenes, rosin, talc,
Fillers such as calcium carbonate and stabilizers such as antioxidants may be added. The thickness of the thermal transferable ink layer 4 is 0.5 to 20 μm.
It is preferably in the range of 1.5 to 8, more preferably 1.5 to 8.
μm is good. Even in the case where the thermal transferable ink layer 4 has a structure of two or more layers, the thickness of all the ink layers is preferably within the above range. In this case, the thickness of each layer is 0.1 to 10 μm, more preferably 0.2 to 4 μm.
μ is preferred. To obtain the thermal transfer material 1 of the present invention, for example, first, the above-mentioned oxidized polyethylene emulsion is coated on the base material 2 to form an intermediate layer. Next, the above-mentioned heat-melting material, colorant, modified resin composition,
Additives are added as necessary, and the mixture is melted and mixed using a dispersion device such as an attritor, or the respective emulsion solutions are stirred and mixed to obtain an ink in the form of a hot melt solution or dispersion liquid. Next, the ink is applied onto the intermediate N3 using an applicator or the like, and dried if necessary, to complete the thermal transfer material 1. The planar shape of the thermal transfer material 1 of the present invention is not particularly limited, but it is generally used in the form of a typewriter ribbon or a wide tape used for line printers. Further, for color recording, it is also possible to use a heat-sensitive transfer material in which heat-melting inks of several different tones are applied in stripes or blocks. [Example] The present invention will be explained in more detail. Example 1.2 Place] Ko. Polyethylene oxide 40 parts (number average molecular weight 1450, m, p, +00°C) rosin acid
10 parts amine (triethanolamine) 5 parts water
160 parts of a 25% solution of the polyethylene oxide emulsion of the above formulation 1 emulsified under pressure and heat was applied onto a 6 μm thick polyethylene terephthalate film using an applicator, and dried at 60'C for 3 minutes. An intermediate layer 3 having a layer thickness of 1.0 μm was provided. Modified resin compositions A, B, C, and D were synthesized by mixing and heating each component according to the compounding ratio shown in Table 1. Ethylene-vinyl acetate copolymer emulsion 30 parts (base resin MI 6, vinyl acetate content 28%, nonvolatile content 25%) Carbon black aqueous dispersion 70 parts Ethylene-vinyl acetate copolymer emulsion 45 parts (base) Resin Ml 15, vinyl acetate content 28%, non-volatile content 25%) ethylene-
Methacrylic acid-styrene copolymer emulsion 20 parts (ethylene content 88%, nonvolatile content 25%) Vinyl acetate-ethylene copolymer emulsion 25 parts (base resin vinyl acetate content 86%, nonvolatile content 25%)
%) Modified resin composition emulsion A 10 parts (inorganic content ff 150%, non-volatile content 25%) Uryu A ethylene-vinyl acetate copolymer emulsion 40 parts (base resin Ml 15, vinyl acetate content 28%, non-volatile content 25) %) ethylene-
Methacrylic acid-styrene copolymer emulsion 40 parts (ethylene content 80%, nonvolatile content 25%) Modified resin composition emulsion A 10 parts (inorganic content 5
0%, nonvolatile content 25%) carbon black water dispersion
10 parts The formulations of the above formulations 2 and 3.4 were uniformly mixed using a propeller type stirrer to form coating liquid 2.3.4.
I got it. Coating liquid 2 was applied onto the intermediate layer using an applicator, and dried with hot air at 60°C for 1 minute until the layer thickness was 0.
．． A first thermally transferable ink layer of 9 μm was obtained. Coating liquid 3 was applied thereon using an applicator, and a second thermal transfer ink layer with a layer thickness of 2.9 μm was formed by drying with hot air at 60°C for 1 minute. Obtained. Further, coating liquid 4 was applied on the intermediate layer in the same manner as in Example 1, and dried with hot air at 60°C for 1 minute to form a layer with a layer thickness of 5.
A thermal transferable ink layer having a thickness of 0 μm was provided to obtain a thermal transfer material of Example 2 of the present invention. Only Example 2 had a three-layer structure. Example 3.4.5 Anal 1 50 parts of ethylene-vinyl acetate copolymer emulsion (base resin MI 15, vinyl acetate content 28%, non-volatile content 25%) ethylene-
Methacrylic acid-styrene copolymer emulsion 20 parts (ethylene content 80%, nonvolatile content 25%) Vinyl acetate-ethylene copolymer emulsion 15 parts (base resin vinyl acetate content 86%, nonvolatile content 25%)
%) Modified resin composition emulsion 8 15 parts (inorganic content 15%, non-volatile content 25%) Ethylene-vinyl acetate copolymer emulsion 45 parts (base resin Ml 6, vinyl acetate content 28%, non-volatile content 25 %) ethylene-
Methacrylic acid-styrene copolymer emulsion 20 parts (ethylene content fi 88%, non-volatile content 25%) Modified resin composition emulsion C 35 parts (inorganic content 30%, non-volatile content 25%) Chayu I Ethylene-vinyl acetate copolymer Emulsion 50 parts (base resin Ml 6, vinyl acetate content 28%, non-volatile content 25%) ethylene-
Methacrylic acid-styrene copolymer emulsion 20 parts (ethylene content 80%, non-volatile content 25%) Modified resin composition emulsion D 30 parts (inorganic content fi
75%, nonvolatile content 25%) The formulations 5, 6, and 7 above were uniformly mixed using a propeller type stirrer to obtain coating liquids 5 and 6.7. In the same manner as in Example 1, an intermediate layer and a first thermally transferable ink layer were provided on a 6 μm thick polyethylene terephthalate film support. Coating liquids 5 and 6.7 were respectively applied on the first ink layer in the same manner as in Example 1 to form a second ink layer. A thermal transfer material was obtained. Comparative Examples 1 and 2.3 A mutual ethylene-vinyl acetate copolymer emulsion 45 parts (base resin Ml 15, vinyl acetate content 28%, non-volatile content 25%) ethylene-
Methacrylic acid-styrene copolymer emulsion 25 parts (ethylene content f! 188%, non-volatile content 25%) Vinyl acetate-ethylene copolymer emulsion 30 parts (base resin vinyl acetate content 86%, non-volatile content 25)
%) Guahodan ethylene-vinyl acetate copolymer emulsion 45 parts (base resin Ml +5, vinyl acetate content 28%, non-volatile content 25%) ethylene-
Methacrylic acid-styrene copolymer emulsion 20 parts (ethylene content 1188%, nonvolatile content 25%) Vinyl acetate-ethylene copolymer emulsion 30 parts (base resin vinyl acetate content 86%, nonvolatile content 25%)
%) Colloidal silica aqueous dispersion 5 parts (non-volatile content 25%) Tetraethylene-vinyl acetate copolymer emulsion 45 parts (base resin Ml 15, vinyl acetate content 28%, non-volatile content 25%) ethylene-
Methacrylic acid-styrene copolymer emulsion 20 parts (ethylene content 88%, nonvolatile content 25%) Vinyl acetate-ethylene copolymer emulsion 25 parts (base resin vinyl acetate content 86%, nonvolatile content 25%)
%) Colloidal silica aqueous dispersion 10 parts (non-volatile content 25%) The formulations of formulations 8, 9 and 10 above were stirred and mixed uniformly in the same manner as in Example 1, and a coating liquid of 8°9, 1O was added. Obtained. Coating liquids 8, 9, and 10 were used as the coating liquid for the second thermal transfer ink layer of Example 1, and the other three types of Comparative Example 1, 2, and 3 were used in the same manner as in Example 1. A thermal transfer material was obtained. Next, the eight types of thermal transfer materials obtained in the above examples and comparative examples were cut into 8 mm width pieces, and printed on recording paper with Bekk smoothness of 2 seconds and 1 [10 seconds] using a thermal printer shown in Fig. 4. went. The recording apparatus shown in FIG. 4 will be explained. 11 is a recording paper which is a recording medium, and 1 is a thermal transfer material. 13 is a thermal head equipped with a heating element 13b. The heating element 13b is provided on the substrate +3a. Further, 16 is a temperature detection element that detects the temperature of the substrate +3a of the thermal head 13, and 17 is a heater that heats the thermal head 13. Both ends of the thermal transfer material l are fed out by a feed roller 4.
1 and winding roller 42, and are sequentially sent out in the direction of arrow a. The thermal head 13 is attached to the carriage 46 and the recording paper! 1 and the thermal transfer material 1 and press the back platen 43 with a predetermined pressure.The carriage 46 moves along the rail 45 in the direction indicated by the arrow, and as it moves, the thermal head 13 performs recording on the recording paper 11. Prior to the recording operation, the heater 17 is energized and the temperature detection element 1 is
In step 6, the temperature of the thermal transfer ink layer is controlled to a predetermined temperature T0 while monitoring the temperature of the substrate 13a. The temperature T0 is controlled to satisfy the condition lower than the temperature (transfer start temperature) T+ at which the transfer of the ink layer 4 to the recording medium 11 starts (0 normal T).
. is preferably set in the range of 35°C to 60°C. The recording medium 1 is heated to a temperature To while traveling along the thermal head 13. In this way, prior to the recording operation, the thermal transfer ink layer is heated to a predetermined temperature T.
. By heating the ink in advance, the temperature distribution of the ink becomes smooth, and it is possible to obtain a recorded image that does not excessively permeate the recording paper. Note that the heater 17 is not necessarily required, that is, the heater 17 is not necessarily required.
Although To may be at room temperature, To was set at (50±3)° C. when printing on the above eight types of thermal transfer materials. Now, the heating element 13b of the thermal head 13, which is arranged at a density of 240 dat/Inch,
, a power of 0.36 w/dot was applied with a width of , and the head was scanned at a speed of 20 cps to obtain a Beck smoothness of 2 seconds and
Printed on 0 second paper. The printing results are shown in Table 2. The recording medium according to Example 1 contains modified resin composition A in the second ink layer, and in Example 2, the ink layer contains modified resin composition A. In Examples 3 and 4.5, the second ink layer contains B, C, and D, respectively. Comparative Examples 1 and 2.3 do not contain the modified resin composition, and Comparative Example 2
．． In No. 3, silica is included in the second ink layer instead. As can be seen from Table 2, it was confirmed that the recording medium according to the present invention exhibited good transferability. Table 2 X Bad

【Effect of the invention】

As explained above, by containing a modified resin composition in which a resin and an inorganic substance are bonded together using a coupling agent in at least one layer of the thermal transferable ink layer, the density is high not only for smooth paper but also for rough paper. , good transferability,
It is possible to obtain sharp and clear printing.

[Brief explanation of the drawing]

FIGS. 1 and 2 are schematic cross-sectional views of a thermal transfer material according to the present invention. FIG. 3 is a schematic conceptual diagram of a modified resin composition according to the present invention. FIG. 4 is a plan view showing an example of an apparatus for printing using the thermal transfer material of the present invention. 1...Thermal transfer material 2...Support 3...Intermediate layer 4...Thermal transferable ink layer 5...First ink layer 6...Second ink Layer 7...Resin 8...Coupling agent 9...Inorganic substance IO...Modified resin composition 11...Recorded object 13...Thermal head +3a...Substrate 13b... Heating element 16... Temperature detection element 17... Heater 41... Delivery roller 42... Winding roller 43... Back platen 45... Rail 46... ···carriage

Claims (1)

[Claims] A thermal transfer recording medium having an intermediate layer and one or more thermal transferable ink layers on a support in this order, characterized in that at least one of the ink layers contains a modified resin composition in which a resin and an inorganic substance are bonded together by a coupling agent. A thermal transfer recording medium.